Breech mechanism.



No. 688,386. Patented Aug. I3, |901. lJ. FQMEIGS & S. A. S. HAMMAR. BREECH MEQHANISM. (Application mea Jan. 1a, 19o (No Model.)

2 Sheetssheat 2.

UNrrlnD STAT-ns l PATENT Ormes. 'A

JOHN FORsYfrn Mmes, or SOUTH BETHLEHEM, AND sIcARD A. s. nAMMAn;

OF BETHLEHEM, PENNSYLVANIA, ASSIGNORS TO THEBETHLEHEM STEEL COMPANY, OnBE-THLEHEM, PENNsYLvANIAI f BRI-:ECH MEcHANlsM'.

SPECIFICATION forming part of Letters Patent No. 680,386', dated August 13, 1901.

Application filed January 18. 1991. Serial No. 43,809. (No model.) A

To @ZZ whom it may concern:

Be it known that we, JOHN FORSYTH Mmes, a citizen of the United States, residing at South Bethlehem, and SIGARD A. S. HAMMAR, a subject of the King of Sweden and Norway,

residing at Bethlehem,l in the county of Northampton and State of Pennsylvania, have invented certain new and useful Improvements in Breech Mechanism, of which the following xo is a specication. j

Our invention relates to breech mechanism for guns, and has forits object to improve and simplifysuch mechanism; and it consists in the features of construction and arrangement I 5 of parts having the general mode of operation substantially as hereinafter more fully set forth.

Referring to the accompanying drawings, wherein We have illustrated a preferred emzo bodiment of Ourinvention, Figure 1 is a trans- A verse section of a breech, showing' a plug therein in its locked position. Fig. 2 is a similar section showing the plug in its unlocked position. Fig. 3 is a longitudinal sec- 5 ,ti-on through the breech, showing collars in the screw-box. Fig. 4 is a diagram illustratng the involute faces of the threads or collars of the breech-plug and screw-box, and Fig, 5 is an enlarged detail/view'of 'the coli gi-dare having inclined pressure sides'.

Among the principal objects of our lnvention we may mention that we provide such a construction that an extended rotation of Pthe breech block or plug is not required in order to engage or disengage it from the screw-box, that the threaded or collared por- "tions of the circumferenceof the breechblock and screw-box are greater than the slotted portions, that the threads or collars on -4'0 the breech-block and screw-box move radially with relation to each other when the breech-block is rotated, that the bearing-surfaces of the threads or collars on the breechblock and screwbox are true and parallel to -4'5 each other and make contact along their whole opposing faces, and even when the block is screwed a little beyond oralittle short ofthe correct position to which it should go the bearing-faces remain true, that there isa uniform and therefore the least possible clearance between the threads or-collars of the breech-block and the screw-box, and consequently' the least possible rotation of the block is required to engage or disengage its threads'or collars from those of the screwbox, and that proper means are provided to secure the seating of the gas-check and the withdrawal of the same, and these and other objects are accomplished by a construction substantially such as is set forth hereinafter. In order to attain vthese and other objects/,we provide the breech-block and screw-boxwith coincide with involute curves, and, further, we construct and arrange the parts substantially as hereinafter set forth.

Thus, referring to the drawings, ythe breech A is provided with a screw-box A', which receives t-hel breech block or plug B, which plug may be supported upon any suitable carrier in any suitable or well-known manner not necessary .to show herein, andv the screw-box may be cylindrical or tapering or of other form, as desired. The interior of the screwbox is divided in the present instance into alternate recesses @j and projections y', the latter having internal threads-cr collars w, and the block has-:alternate projections zo and` recesses w', the lprojections being provided with threads or collars a. Preferably or collars are greater circumferentially than the intermediate recessed or slotted portions, as shown, as lby this construction we are enabled to secure a greater extent of bearingsurface and a better support with a shorter provided with recessed and projecting ortions equal in circumferential extent. internal and external threads orcollars and 'z are so formed that their edges or faces conform to involute curves,`and these curves on the breech-block and screw-box are parallel to each other when the block is in its locked or unlocked position or in any intermediate position,

lars 'one the breech-block move Iradially with threads or collars the edges or faces of which This parallelism is indicated in a, general wayin Fig. 4. The threads or col- *i the projecting portions having the threads block than when the block and screw-box are rte 7 when the breech-block is in place, and even when the block is rotated a little beyond or a little short of the correct position the bearing-faces remain true, and when the block is rotated to unlock the same there is a uniform i clearance, and the least possible rotation of the block is required to disengage the threads or collars.

In order to insure such a movement of the breech-block in the screw-box that will prop- Screw-box.

erly scat the gas-check, the parts are so constructed that the advancing and turning motion of the breech-block, constituting a screw motion, has a pitch or advance which is greater than the pitch of the thread in the The pitch of the thread inthe screw-box may be zero; as when `collars are used. The means by which we accomplish this consists in making the pressure sides of the collars lon the breech-block orthe screw- .box, and preferablyboth, inclined.; Thus, as indicated in Fig. 5, the sides sr and z' of the threads or collars :aand z areI inclined, and

when the breech-blockis rotated, so as' tol bring the threads or collars no and znto engagement, their inclined pressure sidesz gas-check is properly seated.

When collars are used, the rotation of the breech-block to disengage the collars has no effect in forcing the breech-block backward orto detach the gas-check, and. Iwe provide suitable meansv for doing this, shown .in the present instance in the form oi' one or more inclined bearing-ribs s', arranged in the slotted portionor portions of the yscrew-box, so as to engage one of the collars as the breechblock is turned to disengage the collars and so as to force the block outwardly and detach the gas-check.

What we claim is l. A breech-loading gun, the screw-box and breech-block of which are provided :with i threads or collars the faces of which threads or collars coincide with involute curves, subl stantially as described.

ceases ,2. Abreech-loadin gumthescrew-ox and. breechfblocklof whic are prdvided ith alternating slotted land threaded or collared portions, the curves ofthe threads or collars being involute curves, substantially as described. l

3.' Abreech-loading gun, the screw-box and breech-block of which are provided with alternating slotted and threaded 'or collared portions', the threaded or collared portions being circumferentially greater than the intermediate slotted portions, and the curves ofthe threads or collars beinginvolute curves, substantially as described.

4. lIn a breech-loading gun, lthe combination with a screw-box and breech-block each having threads or collars the faces of which coincide with involute curves, .of means to seat the breech-block by an advancing and turning motion constituting ,a screwmotion the pitch'oi' which screw motion is greater than the pitch of the threads-or'collars into which the threads or collars of the breechblock seat, substantially as described.

5,' In a breech-loading gun, the combination with a screw-box, of a breech-block each having collars the-faces of which coincide with involute curves, the pressure sides ofthe collars being inclined, substantial-ly as described.

6. In a breech-loading gun, the combina-,

t-ion with a screw-box and breech-block, each provided with collars, of means for `forcing l f the breech-block outward when it is 'rotated to disengage the collars, substantially asdescribed.

7.. In a breech-loading gun, the combina-i- In testimony Whereot` we have signed our names to this specification in the two subscribing witnesses.

presence of JOHN FoRsYrH Mates.

SIGARD A. S. HAMMAR.I

'- Witnesses:

` ABRAHAM S. SCHROPP,

H. J. ENooH. 

